In portable radio apparatus such as a portable telephone set, the casing is getting more and more compact and low-profile in order to enhance portability. Thus, efforts have been made to install in high density a radio circuit, a speaker, a receiver, and an LCD (Liquid Crystal Display) module in a limited space within the casing.
In general, a speaker is easier to vibrate when the volume of a space present at the rear of the speaker is larger. In the portable telephone set, it is difficult to reserve a sufficient space at the rear of the speaker because of the high-density install; as a result, full performance of a speaker cannot be obtained.
It is requested to prevent an electromagnetic wave from generating a noise in the speaker.
The inventions has been proposed to solve such problems and aims at providing a portable radio apparatus that prevents propagation of an electromagnetic wave from a radio circuit to a speaker and improves sound quality of a speaker.